We have built, using resources of the National Nanofabrication Facility, microlithographic quasi two-dimensional obstacle arrays. These devices are being used to both probe and process biological polymers on these microlithographic surfaces. Using support from this grant, we propose to acquire instrumentation to do highly sensitive realtime fluorescence imaging to observe and analyze the motions of extremely large single polymer molecules through these arrays. The immediate aim of these experiments is to fractionate DNA polymers at the chromosome length scale in a highly reproducible environment. The experience gained in learning how to move very long DNA molecules through synthetic microlithographic surfaces will be exploited in the latter phase of this project to align chromosomal length DNA molecules and analyze both the DNA sequence and other biologically relevant properties.